Welcome to this video lecture on ResFinder. My name is Valeria Bortolaia. I am a senior researcher at the Technical University of Denmark, and I am the curator of ResFinder database. In the next five-ten minutes, I would like you to become familiar with what is ResFinder, and how is ResFinder curated. ResFinder is a repository of antimicrobial resistance genes. It's basically a catalogue of known antimicrobial resistance genes. It was created in 2012, at the Center of Genomic Epidemiology. The idea by then was to find a single, unique place where to collect all known antimicrobial resistance genes. In this way, it would be possible to compare sequence of bacteria with this database, and find out which resistance genes are in the sequences we are analyzing. The idea is indeed quite simple but it represented a revolution in detection of antimicrobial resistance genes. By then, when you wanted to detect an antimicrobial resistance gene, you were targeting specific genes by PCR. By using databases like ResFinder, it is possible to detect all resistance genes without any a priori selection in your strains. Currently, there are more than 2,300 genes conferring resistance to 15 antimicrobial classes but there are continuous updates. ResFinder is a very heavily used database with more than 220,000 searches performed to date. If you are looking for ResFinder from your Internet browser, you will end up in this page. This page, this part of the page at least, is very useful if you are performing analysis of sequences of single isolates. But if you're dealing with Metagenomics sequences, it is actually more relevant to scroll down the page and arrive to the ResFinder database download site. By clicking on this, you will be taken to a second page where there are all databases, but the important part is actually in the top of the page where there is this link to Bitbucket. By clicking this link, it will be possible to open the page with all the repositories of the databases that are created by the Center for Genomic Epidemiology. In this case, you will be interested in the ResFinder database. Click on that, you will be taken to a page where you have a lot of Fasta files. Basically, in ResFinder all antimicrobial resistance genes are collected in Fasta files according to the class to which they confer resistance. So here you will have the Fasta files of aminoglycoside resistance genes, beta-lactam resistance genes and so on. This part is very important for the users, especially when dealing with metagenomics data because these databases can be downloaded and they are amenable to different changes, to be tailored according to the needs of the user. You will be introduced to the way we use these files in MGmapper later on during this course, but it is really, really important to emphasize that there are almost endless possibilities on how to index these files, which ones to include, and so on, that can vary according to your study and your needs. How are the files inserted? What are the criteria for inclusion of files into the database? All the so-called de-facto antimicrobial resistance genes should be there. By de-facto antimicrobial resistant genes, I indicate resistance genes, conferring resistance per se, so not chromosomal genes that confer resistance upon mutations. For these there's actually a different database that is called the Point Mutation database. The source of these genes can be GenBank, publications or users. I actually have almost daily communications with users and they're always very happy to share news about new resistance genes, but they will be uploaded on ResFinder only once there is a GenBank accession number assigned. And finally, it was decided in the inception of the ResFinder database to include all allelic variants, which may not always be the case just because it is difficult to keep up to date all the time, but the intention is, if some variants have been described but they're missing,to include them in the future. Something that is extremely important to notice is that there are continuous updates. So if you are downloading the database and you are using it privately on different servers, remember to check now and then the Bitbucket page where in the right hand part there is a column where updates with the source of the data, the time and the type of update are actually described. I hope you will find the ResFinder useful and I thank you for your attention.